a. Field of the Invention
This invention relates to the steering assembly on bicycles. In particular, this invention relates to the method and apparatus of securing a bicycle handlebar stem to the front wheel fork steerer tube in a manner that is both safe and convenient for the operator. The steering assemblies of this invention are intended to improve upon existing technology in the two areas—handlebar height adjustability and rotation of the handlebar such that the handlebars end up parallel to the front wheel and the vehicle frame for easy storage.
b. Prior Art
Bicycles are often used only occasionally and stored frequently for extended periods of time. Yet, due to the laterally protruding handlebars, storage is not particularly convenient. To date, there have been few bicycle steering assemblies that could be manually (without the use of tools) adjusted in height, and none that are manually height adjustable and rotatable for storage. Increasingly, consumers are demanding more comfort with an easily adjustable wide range of handlebar heights or positions. Height adjustability, using tools, has always been available and recently has been augmented by offering an adjustable tilt up of the horizontal stem section. But so far, manually (without the use of tools) adjustability has never been available on regular bicycles. The word “manually” shall be used in the context of this disclosure to mean “without the use of tools”. In fact, the standard quill type stem found on many bicycles of today requires that a tool be used for height adjustment. While some operators use the tool properly, it has been found that many do not, leading to the potentially unsafe situation of the handlebar rotating differently from the front wheel during riding.
Representative prior art includes:
[1] U.S. Patents    U.S. Pat. No. 5,727,427 Mar. 17, 1998 Nien    U.S. Pat. No. 5,537,878 Apr. 21, 1996 Hartley    U.S. Pat. No. 5,570,614 Nov. 5, 1996 Nastrucci    U.S. Pat. No. 5,680,798 Jul. 30, 1996 Johnson    U.S. Pat. No. 4,433,852 Feb. 28, 1984 Hon
[2] Foreign Patent Documents    JP21130463A2 May 15, 2001 Japan    JP2000153794 Jun. 6, 2000 Japan    JP10119866A2 May 12, 1998 Japan    JP8324479A2 Dec. 10, 1996 Japan    JP8198168A2 Aug. 6, 1996 Japan    JP8091272A2 Apr. 9, 1996 Japan    GB 2 296 224 A Jun. 26, 1996 England    JP8332986A2 Jun. 7, 1996 Japan    EP0687620A1 Dec. 20, 1995 Germany    JP7052862A2 Feb. 28, 1995 Japan
In the prior art there have been no handlebar steering assemblies that could be safely rotated horizontally (rotating about the steering axis) 90 degrees for easy storage. In addition, other than co-pending U.S. patent application Ser. No. 09/823,765 there have been no handlebar stems whose height is adjustable by hand, that can be rotated for storage. A great number of handlebar stems have focused on being light and strong with U.S. Pat. No. 5,095,770 and U.S. Pat. No. 5,680,798 representative of those proposals. However, all are limited by not having the ability to be manually adjustable in height nor can they be rotated for storage.
A number of patents address the issue of storage but not in a useful manner. The most common approach to reducing the width of the handlebar is by breaking the handlebar into pieces and pivoting them. Some examples of this include U.S. Pat. No. 5,570,614, EP 0 687 620 A1, JP10119866A2, and JP07052862A2. Another method used to reduce the width is by tilting one end of the handlebar up in the air making the bicycle narrower but much taller. This is disclosed in U.S. Pat. No. 5,727,427 and JP08332986A2.
U.S. patent application Ser. No. 09/823,765 overcomes the problems of the above-mentioned prior art. The present application compliments application Ser. No. 09/823,765 by including the most straightforward and safe methods for controlled 90-degree rotation of the handlebars and with optional height adjustability if desired. The handling of the bicycle during the rotation only mode is a simpler process than handling the bicycle in the rotation and fold down options used in application Ser. No. 09/823,765.